The invention relates to a hand-held device for transferring a film of, for example, an adhesive, a covering, or colored material from a backing tape onto a substrate.
A hand-held device for transferring a film onto a substrate by pressing a supply of film fixed on a strip of backing tape, using a spatula-like application member is known in the art. The application member typically protrudes out from the body of the hand-held device with the backing tape running over it so that the backing tape will be sandwiched between the application member and the substrate. The hand-held device is manually gripped and the application member is moved across the substrate so that the film is automatically released from the backing tape of the supply and pressed onto the substrate by the application member. Because the application member protrudes from the hand-held device with the film, there is also a risk that the sensitive film could be damaged when the hand-held device is not in use. Damaged film can lead to undesirable defects in the transferred layer of film, leading to undesirable defects during application of the film onto the substrate, especially at the start of the application of the film. In addition, where the film is a colored material or an adhesive, there is a danger that unintended objects could come into contact with the application member while the hand-held device is not being used and the object can be unintentionally coated with the film.
To avoid the drawbacks described above, DE 195 33 567 A discloses a hand-held device of the above-described type which is provided with a protective lid which is pivotably connected to a housing of the hand-held device by a joint and is pivotably mounted between a non-use position, where the application member is covered, and a use position, where the application member is exposed.
EP 0 313 720 B1 (corresponding to U.S. Pat. No. 4,849,064 to Manusch et al.) describes a hand-held device for transferring a film from a backing foil onto a substrate in which a supply reel and a take-up reel for the backing tape are arranged on a replaceable cassette unit which also bears the application member. The associated housing takes on the form of a housing lid. The cassette unit is swivellable, by means of a swivel arm hinged onto the housing. In its use position, the cassette unit resides in the housing lid and the application member projects from the housing lid so that it can be pressed onto the substrate to transfer the film onto the substrate. To replace the cassette unit, it is swivelled out of the housing lid and exchanged with a new cassette.
EP 0 575 790 B, (corresponding to U.S. Pat. No. 5,346,580 to Elges et al.) also, describes a hand-held device having a cassette unit which bears a supply reel, a take-up reel, and an application member. The housing for the hand-held device has an oblong construction and the cassette unit is longitudinally displaceable in the housing between a use position, in which the application member projects outside through an opening in the housing and, thus, can be pressed against the substrate, and a non-use position in which the application member is retracted in the housing. The cassette unit has a rear end that protrudes from the housing. The cassette unit can be pushed into the use position by exerting manual pressure on the rear end of the cassette unit to push the cassette unit against a restoring spring which biases the cassette unit into its non-use position. The cassette unit can be locked in its use position by a spring loaded detent device provided between the cassette and the housing. The detent device has a press-button for releasing the detent to restore the cassette into its non-use position.
But the above known configurations make inefficient use of space because the cover typically needs a relatively large clearance of motion, i.e., the cover""s movement between its use and non-use position requires a relatively large surrounding space. This is also the case in the hand-held device described in EP 0 575 790 B1 because the rear end of the base body protrudes from the housing. If one were to dispose the base body of this hand-held device completely in the housing, the base body would need a relatively large interior free space in the housing.
The present invention provides an improved hand-held device for transferring a film on to a substrate that is spatially more efficient. The hand-held device of the present invention provides a pivotably attached cover for its application member. The cover requires as little clearance of motion as possible and results in a compact design.
In the hand-held device of the present invention, the cover essentially follows the outer contour of the base body during its pivoting movement. The movement of the cover is therefore not directed transversely to the outer contour of the base body, as is the case in the prior art devices, but is directed along the outer contour of the housing. As a result, the clearance gap between the cover and the outer contour of the base body remains substantially constant throughout movement of the cover, thus advantageously exploiting the space available. The cover can be formed to overlap the rim of the base body in a U-shaped fashion both in its covering or non-use position and in its release or use position.
A particularly advantageous embodiment can be achieved when the cover is provided with a range of movement along a circular arc section, the outer contour of the base body preferably also being formed in a corresponding circular arc shape.
In one embodiment of the invention, the cover at least partially covers the base body in its covering or non-use position. In doing so, the cover fulfils its covering function not only for the application member but also for the base body. It is therefore possible within the scope of the invention for the cover to conceal the majority of the base body or to conceal the entire base body when in its non-use position.
In all the embodiments of the invention, it is advantageous that the outer contour of the base body be formed in the shape of a circular section, in at least the section to be covered by the cover, and to mount the cover such that it can be swivelled. In doing so, it is advantageous that the center of curvature of the outer contour of the base body and the swivel axis of the cover lie on essentially the same axis. This minimizes the clearance gap between the inner surface of the cover and the outer contour of the base body so that a compact construction can be achieved.
The cover may be made to be as thin as possible. It is particularly advantageous to form the cover in the form of a section of a circle with the flattened part being beyond the center of curvature in the sense of a secant. This design also improves handling when the size of the cover shaped as a section of a circle is adapted to the size of the user""s hand such that the operating hand can extend over the cover, and the base body can be gripped and held between the thumb and at least one finger of the user""s hand. To improve the grip, it is advantageous to form the grippable side surfaces of the base body such that they are easy to grip, e.g., to make them rough or with furrows or gripping grooves.
The base body can thereby have the shape of an essentially circular disc with the application member projecting radially from the base body. In this case, the clearance of motion between the base body and the cover is to be of such a size that the application member can be swung under the cover or the cover can be swung over the application member by effecting a relative movement between the base body and the cover.